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Full-Text Articles in Engineering

Multifunctional Lightweight Aggregate Containing Phase Change Material And Water For Damage Mitigation Of Concrete, Wenyu Liao, Aditya Kumar, Kamal Khayat, Hongyan Ma Dec 2019

Multifunctional Lightweight Aggregate Containing Phase Change Material And Water For Damage Mitigation Of Concrete, Wenyu Liao, Aditya Kumar, Kamal Khayat, Hongyan Ma

Materials Science and Engineering Faculty Research & Creative Works

This paper presents an innovative concept of multifunctional lightweight aggregate, which is produced by loading phase change material (PCM) into the interior of lightweight sand (LWS) and sealing the surface pores using water. The PCM loaded in the LWS functionalizes it as a temperature management agent in concrete, and the water in surface pores enables internal curing. It has been found that the particle shape and pore structure of crushed expanded shale LWS makes it an ideal carrier for PCM, loading sufficient PCM and maintaining better (compared to natural sand) mechanical interlocking. When coupled with the internal curing effect, the ...


Grain Refinement In Iron-Based Materials, Simon Naumovich Lekakh, Von Richards, Ronald J. O'Malley, Jun Ge Nov 2019

Grain Refinement In Iron-Based Materials, Simon Naumovich Lekakh, Von Richards, Ronald J. O'Malley, Jun Ge

Materials Science and Engineering Faculty Research & Creative Works

A process for manufacturing an iron-based alloy comprising forming targeted fine oxide and/or carbide dispersoids in a melt, and sequentially precipitating transition-metal nitrides on the dispersoids for heterogeneous nucleation of equiaxed grains. An iron-based cast alloy having a highly equiaxed fine grain structure.


Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk Sep 2019

Grain Size Effects In Selective Laser Melted Fe-Co-2v, Wesley Everhart, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

The material science of additive manufacturing (AM) has become a significant topic due to the unique way in which the material and geometry are created simultaneously. Major areas of research within inorganic materials include traditional structural materials, shape memory alloys, amorphous materials, and some new work in intermetallics. The unique thermal profiles created during selective laser melting (SLM) may provide new opportunities for processing intermetallics to improve mechanical and magnetic performance. A parameter set for the production of Fe-Co-2V material with additive manufacturing is developed and efforts are made to compare the traditional wrought alloy to the AM version of ...


A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou Aug 2019

A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

A novel adaptive displacement-controlled test setup was developed for fatigue testing on mini specimens. In property characterization of additive manufacturing materials, mini specimens are preferred due to the specimen preparation, and manufacturing cost but mini specimens demonstrate higher fatigue strength than standard specimens due to the lower probability of material defects resulting in fatigue. In this study, a dual gauge section Krouse type mini specimen was designed to conduct fatigue tests on additively manufactured materials. The large surface area of the specimen with a constant stress distribution and increased control volume as the gauge section may capture all different types ...


Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King Jul 2019

Braze For Ceramic And Ceramic Matrix Composite Components, Sean E. Landwehr, Scott Nelson, Jeremy Lee Watts, Greg Hilmas, William Fahrenholtz, Derek Scott King

Materials Science and Engineering Faculty Research & Creative Works

In some examples, a technique may include positioning a first part comprising a ceramic or ceramic matrix composite and a second part comprising a ceramic or a CMC adjacent to each other to define a joint region at the interface of the first part and the second part. In some examples, the joint region may be heated using at least one of a laser or a plasma arc source to heat the joint region to an elevated temperature. The first and second parts may be pressed together and cooled to join the first and second parts at the joint region ...


Effect Of Slm Build Parameters On The Compressive Properties Of 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Heath Misak, Michael Walker Jun 2019

Effect Of Slm Build Parameters On The Compressive Properties Of 304l Stainless Steel, Okanmisope Fashanu, Mario F. Buchely, Myranda Spratt, Joseph William Newkirk, K. Chandrashekhara, Heath Misak, Michael Walker

Materials Science and Engineering Faculty Research & Creative Works

Selective laser melting (SLM) is well suited for the efficient manufacturing of complex structures because of its manufacturing methodology. The optimized process parameters for each alloy has been a cause for debate in recent years. In this study, the hatch angle and build orientation were investigated. 304L stainless steel samples were manufactured using three hatch angles (0◦, 67◦, and 105◦) in three build orientations (x-, y-, and z-direction) and tested in compression. Analysis of variance and Tukey's test were used to evaluate the obtained results. Results showed that the measured compressive yield strength and plastic flow stress varied when ...


Mechanical Properties Of Heusler Alloys, Wesley Everhart, Joseph William Newkirk May 2019

Mechanical Properties Of Heusler Alloys, Wesley Everhart, Joseph William Newkirk

Materials Science and Engineering Faculty Research & Creative Works

Heusler alloys have been a significant topic of research due to their unique electronic structure, which exhibits half-metallicity, and a wide variety of properties such as magneto-calorics, thermoelectrics, and magnetic shape memory effects. As the maturity of these materials grows and commercial applications become more near-term, the mechanical properties of these materials become an important factor to both their processing as well as their final use. Very few studies have experimentally investigated mechanical properties, but those that exist are reviewed within the context of their magnetic performance and application space with specific focus on elastic properties, hardness and strength, and ...


Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang Apr 2019

Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang

Materials Science and Engineering Faculty Research & Creative Works

Effective regeneration of bone defects caused by trauma or chronic diseases is a significant clinical challenge. Bone deficiency is overcome using treatments that rely on bone regeneration and augmentation. While various treatments have been investigated with encouraging results, complete and predictable bone reconstruction is often difficult [1]. Synthetic bone grafts have advantages such as consistent quality, safety, and good tissue tolerance. They usually function as inert or osteoconductive implants. Encouraging results from synthetic grafts have been reported. For instance, hollow hydroxyapatite (HA) microspheres showed the ability to facilitate bone repair in rats with non-healing calvarial defects [2,3]. However, new ...


Hydration Of Binary Portland Cement Blends Containing Silica Fume: A Decoupling Method To Estimate Degrees Of Hydration And Pozzolanic Reaction, Wenyu Liao, Xiao Sun, Aditya Kumar, Hongfang Sun, Hongyan Ma Apr 2019

Hydration Of Binary Portland Cement Blends Containing Silica Fume: A Decoupling Method To Estimate Degrees Of Hydration And Pozzolanic Reaction, Wenyu Liao, Xiao Sun, Aditya Kumar, Hongfang Sun, Hongyan Ma

Materials Science and Engineering Faculty Research & Creative Works

Determination of degrees of hydration/reaction of components of blended cementitious systems (i. e., cement and SCMs: supplementary cementitious materials) is essential to estimate the systems' properties. Although the best methods for determining degrees of reaction of different SCMs have been recommended by RILEM TC238, they rely on either expensive equipment (e.g., nuclear magnetic resonance) or time-consuming sample preparation and data processing (e.g., backscattered electron image analysis). Furthermore, these methods cannot simultaneously characterize degree of hydration of cement and degree of reaction of SCMs. A novel decoupling method, which can simultaneously estimate the degree of hydration of cement ...


Characterization Of Mgal₂O₄ Sintered Ceramics, Nina Obradovic, William Fahrenholtz, Suzana Filipovic, Cole Corlett, Pavle Dordevic, Jelena Rogan, Predrag J. Vulic, Vladimir Buljak, Vladimir Pavlovic Apr 2019

Characterization Of Mgal₂O₄ Sintered Ceramics, Nina Obradovic, William Fahrenholtz, Suzana Filipovic, Cole Corlett, Pavle Dordevic, Jelena Rogan, Predrag J. Vulic, Vladimir Buljak, Vladimir Pavlovic

Materials Science and Engineering Faculty Research & Creative Works

Single phase MgAl2O4 was made from a one-to-one molar ratio of MgO and Al2O3 powders mixed using ball-milling. Mixtures of MgO and Al2O3 were subsequently treated in planetary ball mill for 30, 60, 90 and 120 minutes in air. The aim of this study was to examine phase composition, microstructure, and densification behavior of sintered specimens. After sintering in dilatometer at 1500 °C, the powder was converted to single phase MgAl2O4. The results show that mechanical activation improved the densification behavior of MgAl2O4 sintered specimens ...


Biodegradable Composite Scaffold For Repairing Defects In Load-Bearing Bones, D. E. Day, Ali Mohammadkhah Mar 2019

Biodegradable Composite Scaffold For Repairing Defects In Load-Bearing Bones, D. E. Day, Ali Mohammadkhah

Materials Science and Engineering Faculty Research & Creative Works

A tissue scaffold for repair and regeneration of bone hard tissue or muscle, skin, or organ soft tissue, including load-bearing bone tissue, the scaffold comprising a core of biocompatible, biodegradable inorganic glass fibers; and a biocompatible, biodegradable, flexible polymer film surrounding the core and adhered to the core.


Control Upstream Austenite Grain Coarsening During Thin Slab Casting Direct Rolling (Tscdr) Process, Tihe Zhou, Ronald J. O'Malley, Hatem S. Zurob, Mani Subramanian, San-Hyun Cho, Peng Zhang Feb 2019

Control Upstream Austenite Grain Coarsening During Thin Slab Casting Direct Rolling (Tscdr) Process, Tihe Zhou, Ronald J. O'Malley, Hatem S. Zurob, Mani Subramanian, San-Hyun Cho, Peng Zhang

Materials Science and Engineering Faculty Research & Creative Works

Thin-slab cast direct-rolling (TSCDR) has become a major process for flat-rolled production. However, the elimination of slab reheating and limited number of thermomechanical deformation passes leave fewer opportunities for austenite grain refinement, resulting in some large grains persisting in the final microstructure. In order to achieve excellent ductile to brittle transition temperature (DBTT) and drop weight tear test (DWTT) properties in thicker gauge high-strength low-alloy products, it is necessary to control austenite grain coarsening prior to the onset of thermomechanical processing. This contribution proposes a suite of methods to refine the austenite grain from both theoretical and practical perspectives, including ...